Marine propulsion apparatus



Dec. 6, 1966 c. SABLE MARINE PROPULSION APPARATUS 2 Sheets-Sheet 1 FiledNov. 23, 1964 Car/ JaA/e INVENTOR. WM Wag m E N M r r A Dec. 6, 1966 c.SABLE MARINE PROPULSION APPARATUS 2 Sheets-Sheet 2 Filed Nov. 23, 1964(ar/ Jab/e INVENTOR.

United States Patent Ofiice 3,289,628 Patented Dec. 6, 1966 3,289,628MARINE PROPULSION APPARATUS Carl Sable, Box 747, Seguin, Tex. Filed Nov.23, 1964, Ser. No. 413,224 3 Claims. (Cl. 11537) The present inventionrelates to a new and improved marine propulsion apparatus and moreparticularly to a marine propulsion apparatus employing a single powersource to drive two or more propellers independently of each other.

Due to the space and weight limitations as well as cost factors, marinepropulsion apparatus heretofore available for relatively small andmedium size power boats leaves much to be desired from the standpoint ofoperating etficiency and maneuverability in handling. A single propellercraft has the inherent disadvantage of poor steerage, particularly whendocking or moving astern, as well as the loss of propulsion in the eventthe propeller or other portion of the drive train becomes damaged ordisabled. Although having a twin engine and twin propeller arrangementprovides much better steering than is available with a single propeller,the twin engine arrangement adds undesirable features which largelynegate any overall advantage in operation, particulanly in medium sizeand relatively small craft. The disadvantages of twin engines includethe additional cost of a second power source, the cost of separatereduction gears coupled to the transmissions in those boats requiringreduction gears, the additional weight of the hull and the second engineas well as the sacrifice of additional space and the increase inmaintenance and operating cost incurred by twin engine apparatus.

Also, with conventional single propeller propulsion apparatus heretoforeused, the engine is rigidly mounted in the hull in an inclined positionand at substantially the same angle of inclination as the propellershaft in order to maintain proper alignment between the engine and thepropeller shaft. As a result, the noise and vibration from the operationof the engine and the propeller are transferred to the hull, creatingannoying sounds and vibrations which disturb the boat occupants.Furthermore, the mounting of the engine in an inclined positionincreases the required deck height of the craft and also in someinstances interferes with engine oiling and fuel distribution.

It is an object of the present invention to provide a new and improvedmarine propulsion apparatus having the advantages of being driven by twoor more propellers operated independently of each other without havingthe disadvantages of twin engines and having the further advantage ofautomatic synchronization of the propellers which is difficult to obtainwith dual engines,

It is also an object of the present invention to provide a new andimproved marine propulsion apparatus constructed and arranged so a toenable the engine to be mounted in a substantially horizontal positionin the vessel.

A further object of the present invention is to provide a new andimproved marine propulsion apparatus wherein a single engine is adaptedto drive counterrotating propellers independently of each other.

Still a further object of the present invention is to provide a new andimproved marine propulsion apparatus wherein a flexible connection isprovided between a power source and a pair of propeller drives fordampening the noise and vibration of the operation of the engine and thepropellers and for protecting the drive train from damage in the event apropeller strikes a submerged object.

Still another object of the present invention is to provide a new andimproved marine propulsion apparatus including a single power source anda pair of propellers having an endless belt drive mechanism connectedand arranged so as to enable the propellers to be rotated in the same oropposite directions in synchronization with each other, as desired.

Yet another object of the present invention is to provide a new andimproved marine propulsion apparatus with a single engine resilientlymounted in a hull and with an endless flexible belt drive operablyconnecting the engine and a pair of propeller drive mechanisms forsimultaneously operating the propellers with the single engine.

Still a further object of the present invention is to provide a new andimproved marine propulsion apparatus including a single engine, a pairof transmissions connected to such engine by means of a flexible drivetrain for driving a pair of propellers independently of each other withthe single engine and means for resiliently mounting the engine todampen or eliminate vibration from the hull.

And still a further object of the present invention i to provide a newand improved marine propulsion apparatus including a single engine whichis mounted substantially horizontally in a boat hull, a pair of inclinedpropeller shafts extending through the boat hull, transmissions operablyconnected to each of said shafts for se lectively directing the rotationof each of the shafts independently of the other and flexible drivemeans connecting each of such transmissions with the single engine fordriving such propellers.

.Still another object of the present invention is to provide a new andimproved marine propulsion apparatus including a single engine and avariable gear reduction means for rotating a plurality of propellerdrive mechanisms at various speeds.

The preferred embodiment of this invention will be describedhereinafter, together with other features thereof, and additionalobjects will become evident from such description.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingforming a part thereof, wherein an example of the invention is shown,and wherein:

FIG. 1 is an elevational view showing the engine and the drive trainapparatus of the present invention in position in a boat hull;

FIG. 2 is a plan view showing the flexible belt drive assembly forconnecting a single engine to a pair of transmissions in the marinepropulsion apparatus of the present invention;

FIG. 3 shows a gear and pulley arrangement of the FIG. 5 is a viewshowing details 'of construction of an' alternate gear arrangement inthe apparatus of the present invention for driving the propellers; and

FIG. 6 illustrates another gear arrangement in the apparatus of thepresent invention for driving a' pair of propellers with a single powersource.

The marine propulsion apparatus of the present invention, which isdesignated generally by the letter A, is shown in FIG. 1 of the drawingsmounted in a boat B. Briefly, as best seen in FIG. 2 of the drawings,such apparatus A comprises a pair of gear or fluid drive transmissions Twhich are operably connected to a single power source or engine E bymeans of a flexible drive apparatus F,'as will be 'described in moredetail hereinafter. Such transmissions T are provided for rotating apair of propellers P to drive or propel the boat or vessel B. As will beexplained more fully hereinafter, the apparatus A of this inventionmakes available for use in relatively small and medium size power boatsa marine propulsion apparatus which eliminates several of thedisadvantages inherent in dual engine marine propulsion installationsbut which does provide the type of steerage or maneuverability andpropeller efliciency found only in vessels having dual engines and dualpropellers.

Considering now the apparatus A of this invention more in detail, theengine or power source E, which is normally a gasoline or diesel engine,is mounted in a substantially horizontal position (FIG. 1) in the boathull B and is operably connected to a pair of propeller shafts 10, whichare positioned on opposite sides of the center line 12 of the boat B andpreferably spaced equal distances therefrom. Such shafts extend throughthe boat hull B and are normally mounted in an inclined positionrelative to the engine E and the bottom of the boat hull B. With thisarrangement, the deck 11 is lower than in conventional boats whichprovides more usable space in the hull and increases the overallstability of the boat hull B.

As shown in the drawings, the engine E is provided with a fly wheel 15which is mounted on the engine crank shaft 13. Such fly wheel or drivewheel 15 is shown as having gear teeth 15a formed around the outerperimeter thereof for engaging and driving a pair of gears 16 and 17,respectively. Each of the gears 16 and 17 has gear teeth 16a and 17a,respectively, thereon corresponding to the gear teeth 15a, and also,each of the gears 16 and 17 has one or more sprockets or pulleys 16b and17b, respectively, for driving one or more flexible belt drives such asV-belts or geared belts 19 comprising the flexible drive apparatus F.The gears 16 and 17 are mounted on shafts 26 and 27, respectively, whichare supported by bearings 26:: and 27a. Such shafts 26 and 27 aremounted in a housing (not shown) which is secured to the engine E orcarried on other suitable mounting means, as desired. It can beappreciated that the size of the gears 16 and 17 as well as the size ofthe pulleys 16b and 17b may be of any suitable size desired, dependingupon the characteristics of the particular craft and the power means forpropelling it. Also, it can be appreciated that any number of V-beltsand pulleys may be employed in the flexible drive train F connecting thepower source E and the transmissions T' Without departing from thespirit and scope of the present invention.

As shown in FIG. 2 of the drawings, a suitable transmission T isconnected to the inboard end of each propeller shaft 10 for driving thepropeller P mounted at the outboard ends of each propeller shaft in theusual manner. Each of the transmissions T is provided with pulleys 21for receiving the flexible drive belt 19, which operably connects theengine E and such transmissions T.

As best seen in FIGS. 1 and 2 of the drawings, the transmissions T aremounted in inclined positions relative to the boat hull B to accommodatethe inclined pro eller shafts 10. With the engine E being mounted in asubstantially horizontal position, the flexible belts 19 are disposed ina nonplanar relationship between the pulleys 16b and 17b on the engine Eand the pulleys 21. Also suitable idler gears or pulleys (not shown) arepreferably provided for taking up slack in the flexible drive belts 19and for urging such belts into engagement with such pulleys in a mannerWell known in the art.

The transmissions T are adapted to be operated independently of eachother and normally have forward, neutral and reverse positions forcontrolling the direction of rotation of the propellers P and forpropelling the boat B. However, if it is desired, the transmissions Tmay have multiple speed forward gears to provide a greater flexibilityin the propulsion apparatus of the present invention. It will beappreciated that with separate or independent controls for each of thetransmissions T, the operator of the boat propelled by the apparatus Aof this invention will be enabled to drive both propellers P forward orboth propellers in reverse, as desired. Also, either transmission T maybe put in a neutral position and the boat operated with only onepropeller, which may be the case in the event one of the propellersshould strike a submerged object or otherwise become damaged ordisabled. Also, it should be noted that with the apparatus of theinvention a single throttle control (not shown) is used for controllingthe speed of the power source or engine E and that therefore, the speedsof the propellers P are automatically synchronized to provide foroptimum operating efliciency. Furthermore, when one of the propellers Pis being driven forward and the other propeller is being driven in areverse direction, which is frequently the case in turning the vessel orin docking it, an increase or decrease in the engine speed will effect acorresponding increase or decrease in the rate of turn of the vessel,thus enabling the operator of the boat to control the rate at which itis turned.

While the arrangement of the gears 15, 16 and 17 shown in FIGS. 2 and 3of the drawings will normally cause both of the propellers P to turn orrotate in a counterclockwise direction when driving or propelling theboat forward, if it is desired, the propellers P may be made to turn inopposite directions or to counterrotate by employing one of the geararrangements shown in FIGS. 46 of the drawings. In the alternate drivearrangement shown in FIG. 4, the fly wheel or drive gear 35 is adaptedto rotate the gears 36 and 37, respectively, in opposite directionsrelative to each other. Such gear or fly wheel 35 has internal teeth 35aformed therein for engaging teeth 36a of the gear 36 and also externalteeth 35b which are provided for engaging corresponding teeth 37a of thegear 37. Thus, when the gear 35 is rotated, it will rotate the gears 36and 37 in opposite directions relative to each other. Such gears 36 and37 have pulleys (not shown) which are similar to the pulleys 16b and 17bfor driving the pair of transmissions T and for rotating the propellersP in opposite directions to drive the boat B. With the FIG. 4 geararrangement, the engine E, which is normally aligned axially with thefly wheel 35, may be positioned in an off-center relationship relativeto the center line 12 of the boat hull B or, when the engine E ismounted in a center relationship on the center line 12, the pulleys 16band 17b, respectively, which are connected to the gears 36 and 37 may beconnected to the transmissions T by belts 19 of unequal lengths.

With the gear drive arrangement shown in FIG. 5 of the drawings, a flywheel 45 has internal teeth 45a formed therein for engaging the gear 46which, as shown, is positioned radially inwardly from the outerperiphery of the gear 45. Such gear 46, which has teeth 46a formedthereon, is adapted to drive the gear 47 which is also positionedradially inwardly relative to the outer periphery of the gear 45 andadjacent the gear 46. Such gears 46 and 47 are also adapted to rotatedrive pulleys (not shown) which are similar to the pulleys 16b and 17b,respectively, shown in FIG. 2 of the drawings which are adapted toreceive flexible V-belts 19 for driving the transmissions T. As seen inthe drawings (FIG. 5), the gears 46 and 47 are driven or rotated inopposite directions relative to each other and are consequently adaptedto drive the transmissions T and the propellers P in opposite directionsrelative to each other while propelling the vessel B forwardly. Also,with the FIG. 5 embodiment of the present invention, when the engine islocated in a center position, such flexible drive members F may besubstantially equal in length with the slight offset of the gears 46 and47 from the center of the gear 45 being taken up by means of idlerpulleys (not shown) or the length of the drive belt to thestarboard'transmission may be shorter than the belt to the porttransmission or, if desired, the engine E may be ofiset slightly fromthe center line 12 of the boat B and drive belts of equal lengths used.

In the gear and pulley arrangement shown in FIG. 6 of the drawings, agear 55 which is normally adapted to be driven by the engine crank shaft13 is provided for driving a gear 56 which in turn is adapted to drive agear 57. Each of the gears 56 and 57 have pulleys 56b and 57b,respectively, which are adapted to receive the endless belts 19 fordriving the transmissions T. It will be appreciated that with the FIG. 6gear and pulley arrangement, the gears 56 and 57, respectively, aredriven or rotated in opposite directions relative to each other foroperating the transmissions T, to cause the propellers P tocounter-rotate or rotate in opposite directions relative to each otherfor driving or propelling the boat B.

In using the apparatus of the present invention to propel a boat B, theoperator will have a single throttle and dual gear shift or transmissioncontrols to manipulate and with such single throttle, the speed ofrotation of the two respective propellers P will automatically be thesame, thus providing synchronization of the propellers P. Then to reduceor increase the speed of the boat B, the operator needs to change only asingle throttle setting and the speed of the boat is changed uniformly.When the operator of a craft having the marine propulsion apparatus ofthe present invention wishes to bring the craft to a dock, he mayreverse the port propeller and neutralize or go forward with thestarboard propeller to effect a turning action of the boat. Or, theoperator may, upon reaching the dock, reverse either or both propellersor drive either or both forward, as he desires.

Thus, it can be appreciated that the apparatus of the present inventionhas great versatility as compared to the prior art construction and hasmany of the advantages of a dual engine, dual propeller craft withoutthe disadvantages usually found with such craft.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What is claimed is:

1. A marine propulsion apparatus for propelling a boat hull including:

(a) a single engine mounted in said boat hull,

(b) drive gear means connected to said single engine for rotationthereby,

(c) a pair of driven gear means connected to said drive gear means,

(d) first pulley means with each of said pair of gear means,

(e) a pair of propeller shafts mounted in said boat hull with propellersconnected thereto,

(f) transmission means having forward, neutral, and reverse positionsconnected to each of said propeller shafts for rotating such shaftsindependently of each other,

(g) second pulley means connected to each of said transmission means,and

(h) flexible belt drive means connecting said first pulley means andsaid second pulley means for operably connecting said transmission meansto said engine means for driving said transmission means and saidpropellers connected thereto.

2. A marine propulsion apparatus for propelling a boat hull including:

(a) a single engine mounted in said boat hull in a substantiallyhorizontal position,

(b) drive gear means on said engine,

(c) a pair of driven gears mounted on shafts disposed substantiallyparallel to the longitudinal axis of said engine,

(d) first pulley means with each of said pair of gears,

(e) a pair of substantially parallel propeller shafts mounted in saidboat hull on opposite sides of said engine and disposed downwardly andrearwardly with respect thereto,

(f) said propeller shafts being substantially the same length and havingpropellers mounted thereon,

(g) second pulley means connected to each of said propeller shafts,

(h) a first flexible belt drive means connecting one of said first pairof pulley means and one of said second pair of pulley means for rotatingone of said pair of propeller shafts,

(i) a second flexible belt drive means connected to the second of saidfirst pair of pulley means and the second of said second pair of pulleymeans for rotating said second of said pair of propeller shafts, and

(j) both of said flexible belt drive means being disposed substantiallyperpendicular to the longitudinal axis of said engine.

3. The apparatus defined in claim 2 including transmission means havingforward, neutral, and reverse positions connected to each of saidpropeller shafts for rotating such propeller shafts independently ofeach other.

References Cited by the Examiner UNITED STATES PATENTS 5,371 4/1873 Lee-37 3,112,728 12/1963 Krause ll537 3,207,119 9/1965 Holder 1l537 FERGUSS. MIDDLETON, Primary Examiner,

MILTON BUCHLER, Examiner.

T. MAJOR, Assistant Examiner.

1. A MARINE PROPULSION APPARATUS FOR PROPELLING A BOAT HULL INCLUDING:(A) A SINGLE ENGINE MOUNTED IN SAID BOAR HULL, (B) DRIVE GEAR MEANSCONNECTED TO SAID SINGLE ENGINE FOR ROTATION THEREBY, (C) A PAIR OFDRIVEN GEAR MEANS CONNECTED TO SAID DRIVE GEAR MEANS, (D) FIRST PULLEYMEANS WITH EACH OF SAID PAIR OF GEAR MEANS, (E) A PAIR OF PROPELLERSHAFTS MOUNTED IN SAID BOAT HULL WITH PROPELLERS CONNECTED THERETO,